Optical modulators may operate at a bias point based on a direct current (DC) bias signal driving the modulator at a certain voltage level. An operating parameter of an optical modulator such as the bias point may, however, drift over time due to environmental perturbations and aging effects on the modulator. Such a drift in an operating parameter may lead to impaired performance from the optical modulator. Thus, precision bias control of an optical modulator may be of significant utility in commercial and non-commercial applications relying on modulation of optical signals.